James findlay-guild



2 Sheets--Shee.t l. J. F. GUILD.

DRIVING GEAR.

(No Model.)

Patented Nov. 14, 1893.

In venfo'r;

#1791 eaves; 1 ggazkz 2 Sheets-Sheet 2.

(No Model.)

J. F. GUILD.

DRIVING GEAR.

m: NATIONAL LI'YHOGRAFHING eoMPANv,

WASHINGTON. D. c.

UN ITED STATES PATENT ()FFICE.

JAMES FINDLAY GUILD, OF DUNDEE, SCOTLAND.

'DRlVlNG-G'EAR.

SPECIFICATION forming part of Letters Patent No. 508,701, dated November14, 1893. Application filed June 13, 1893. Serial No. 477,509-.(hlo'miodeld Patented in England October 13, 1892, No. 18,3,

To all whom it may concern? Be it known that I, JAMES'FINDLAY GUILD, M.I. N. A., consulting engineer and steamshi ps urveyor,a subjectoftheQueen of Grcat" Brltaln, residing at 8-3 Ancrum Road, Dundee,"Scotland, have invented new and useful I|n-' provements in Driving-Gearfor Velocipedes and Crank-Driven Mechanism generally, (for incline, andthough designed more especially for use in connection with velocipedes,is applicable to crank driven mechanism of all kinds.

This invention consists mainly in the introduction of a spring orsprings between the crank and the shaft or other mechanism driventhereby.

I will now proceed to describe this in vention as applied tovelocipedes. Its application to other mechanism will be so wellunderstood that any further description will be unnecessary.

The chain wheel or driving wheel, as the case may be, of the velocipedeis mounted upon the crank shaft, or upon a socket to be fixed on thecrank shaft, so that it may be free to rotate thereon. In the side ofthis wheel is made an annular recess or groove to receive a spiralspring suitably bent in a circular form to lie within the said groove. Acover plate or disk is provided to inclose the said groove and retainthe springin position. An arm rigidly secured to the crank shaft orsocket is made to project through a suitable slot in the side of therecess containing the spring and bear against one end of the saidspring. The other end of this spring bears against a proj ectionin thesaid annular spring chamber.

It Will be seen that rotary motion given to the crank shaft will beconveyed to the chain or driving wheel, as the case may be, through theintervention of the spring contained in the annular recess. On thespring receiving ithe thrust of the arm occasioned by the downwardpressure of either of the treadles git is compressed in proportion tothe power applied. This compression if on a level road with easy drivingis just sufficient to relieve the rider of the concentrated resistanceof gthe machine. When the 'machine is being :driven hard the recoilofthe spring occasioned by the greater amount of compression carries thecrank over the dead centers without depending upon the momentum of themachine for this purpose as in the case of machines of ordinaryconstruction. In short this device absorbs the excess of power given outbythe rider during one part of the stroke and'gives it out to themachine during the other part of the stroke.

In some cases I find it advisable to employ two or more short springs inplace of one long one. These are each operated upon by a separate armprojecting from the crank shaft or socket and of course each bears upona separate projection formed within the annular spring chamber.

In order that my invention may be more fully understood-and carried intopractice I will now proceed to describe the same with reference to theaccompanying two sheets of drawings of which- Figure 1 is anelevation,and Fig. 2 across section of one form of the hereinbeforedescribed device as applied to the chain Wheel of a velocipede. Figs. 3and 4 are similar views of a modified arrangement of the same.

As shown at Figs. 1 and 2 a short sleeve a is keyed upon the crank shaftb of the velocipede and carries at one end a radially projecting arm 0which is inclined to the crank shaft at such an angle that its endenters an annular groove or recess 01 formed in the face of the web ofthe chain wheel 6. In this groove is placed a helical spring f bearingat one end against a stop g, formed in one with the chain wheel e, andat the other against the radial arm 0 extending from the sleeve a. Thespring is retained within the groove by the cover plate h which isscrewed or otherwise attached to the face of the chain wheel e. Aportion of this plate his removed so as to allow of the clear passage ofthe radial arm a into the groove cl. The central part of this coverplate as shown at Fig. 2 bears against the end of the sleeve a and soserves to retain the chain wheel 6 in position.

In the arrangement shown at Figs. 3 and 4 the chain wheel is arranged tosupport two springs f and the sleeve a is provided with two radial armsa one to bear against the end of each of the said springs. The coverplate is of course modified in construction to allow of the entry of thetwo arms a into the grooves d. In other respects the parts are similarto those already described as an inspection of the drawings will show.

It will be understood that the hereinbefore described device maybeplaced upon the axle of a chain wheel with equal success in working, itbeing only necessary to reverse the device so that it. may rotate in theopposite direction.

\Vhat I claim is 1. In a gear mechanism, the combination of a shaft,agearwheel loosely mounted thereon, having a groove in the face of web,an arm secured to the shaft beside the said wheel, a spring situated inthe said groove, and bearing at one end against a stop on the wheel andat the other end on the said arm, and a confining plate for holding thespring in the groove, substantially as hereinbefore setforth.

2. The combination of the crank shaft of a velocipede, a driving wheelmounted loosely thereon, and having an annular groove in the face of itsweb, the arm 0 secured tothe shaft and having its outer portion inclinedso as to enter the said groove, and a spring situated in the said groovebetween the said arm and a stop on the wheel, substantially as hcrelnbefore set forth.

3. The combination of a shaft, a gear wheel loose thereon, having arecess orgroove in one of its faces concentric with the shaft, an arm asecured to the shaft, a plate It secured to the wheel and havinga recesscorresponding with the recess in the wheel and having a portion adjacentto the arm cremoved, and the spring situated in the said recesses,substantially as hereinbet'ore set forth.

4. The combination of the crank shaft of a velocipede, a sleeve a keyedthereto, an arm 0 carried by the said sleeve, a driving wheel having aportion adjacent to the arm a removed and mounted loosely upon saidsleeve, and provided with the groove d in its side face, the plate Itsecured to the wheel, and a spring in the said groove between the wheeland the plate and hearing at one end against the said arm 0,substantially as hereinbefore set forth.

J. F. GUILD.

Witnesses:

Tno. BROWN, ADAM BOWMAN, Law Clerks, N0. 41 Reform Street, Dundee,

Scotland.

